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Darwin, Charles, 1809-1882

"The formation of vegetable mould through the action of worms, with observations on their habits"

My son collected all from one of
the holes, the area of which was 5.32 square feet, and they weighed
7.97 ounces. Assuming that this amount had accumulated in six
months, the accumulation during a year on a square yard would be
1.68 pounds, which, though a large amount, is very small compared
with what, as we have seen, is often ejected on fields and commons.
When I visited the abbey on June 22, 1877, the old man said that he
had cleared out the holes about a month before, but a good many
castings had since been ejected. I suspect that he imagined that
he swept the pavements oftener than he really did, for the
conditions were in several respects very unfavourable for the
accumulation of even a moderate amount of castings. The tiles are
rather large, viz., about 5.5 inches square, and the mortar between
them was in most places sound, so that the worms were able to bring
up earth from below only at certain points. The tiles rested on a
bed of concrete, and the castings in consequence consisted in large
part (viz., in the proportion of 19 to 33) of particles of mortar,
grains of sand, little fragments of rock, bricks or tile; and such
substances could hardly be agreeable, and certainly not nutritious,
to worms.
My son dug holes in several places within the former walls of the
abbey, at a distance of several yards from the above described
bricked squares.


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